docs: def modify_menu_items(self, menu_items):
          """
          If the 'use_specific' value on the menu instance indicates that the
          behaviour is desired, and the 'parent page' has a
          'modify_submenu_items()' method, send the menu items to that for
          further modification and return the modified result.
  
          The supplied ``menu_items`` might be a GeneratorType instance returned
          by 'prime_menu_items()' or a list.
  
          Subclasses of ``MenuFromPage`` are responsible for ensuring the page is
          'specific' by this point if it needs to be. (The 'modify_submenu_items'
          method will not be present on a vanilla ``Page`` instances).
          """
          parent_page = self.parent_page_for_menu_items
          modifier_method = getattr(parent_page, 'modify_submenu_items', None)
          if not self.use_specific or not modifier_method:
              return menu_items
  
          ctx_vals = self._contextual_vals
          opt_vals = self._option_vals
          kwargs = {
              'request': self.request,
              'menu_instance': self,
              'original_menu_tag': ctx_vals.original_menu_tag,
              'current_site': ctx_vals.current_site,
              'current_page': ctx_vals.current_page,
              'current_ancestor_ids': ctx_vals.current_page_ancestor_ids,
              'allow_repeating_parents': opt_vals.allow_repeating_parents,
              'apply_active_classes': opt_vals.apply_active_classes,
              'use_absolute_page_urls': opt_vals.use_absolute_page_urls,
          }
          if isinstance(menu_items, GeneratorType):
              # 'modify_submenu_items' methods expect 'menu_items' to be a list
              menu_items = list(menu_items)
          return modifier_method(menu_items, **kwargs)